Re: [Ksummit-discuss] [MAINTAINERS SUMMIT] Moving debugfs file systems into sysfs

[Sudeep Holla <sudeep.holla@arm.com>]

On Wed, Oct 03, 2018 at 02:13:53PM +0100, Mark Brown wrote:
> On Wed, Oct 03, 2018 at 11:06:33AM +0100, Sudeep Holla wrote:
> > On Tue, Oct 02, 2018 at 06:37:43PM -0300, Mauro Carvalho Chehab wrote:
> 
> > > Even if it won't be possible to crash the Kernel or escalate
> > > privileges, I suspect that several stuff in debugfs should never
> > > be enabled on production systems, as they may reveal things like
> > > memory addresses and other stuff that could be used to help someone
> > > to crack a system.
> 
> > I completely agree with that. Recently I reviewed patches to support
> > power management on some ARM platforms which had complete system clock
> > control in debugfs. It even had access to many system controls that it
> > can send to remote system control processor which we really don't want
> > in production systems.
> 
> This is why I've always strongly resisted making it possible to write to
> the regmap or regulator debugfs files; there is code for writing to the
> regmap ones but you need to patch the kernel to enable it.

Ah, that's better. Next time I see anything around debugfs where
restricting write is a must, I will suggest something on similar lines
so that they need that extra tiny patch to get it enabled. Thanks for
the pointers.

--
Regards,
Sudeep